(x + 2)² - 10 = 0 (assuming it's equal to zero)
Expand the binomial: (x + y)² = x² + 2xy + y²
Thus, x² + 4x + 4 - 10 = 0
x² + 4x - 6 = 0
[tex]x = \frac{-4 +_- \sqrt{16 + 24}}{2}[/tex] (by quadratic formula)
[tex] = \frac{-4 +_- \sqrt{40}}{2}[/tex]
[tex] = \frac{-4 +_- 2\sqrt{10}}{2}[/tex]
[tex] = -2 + \sqrt{10}[/tex], since we're taking the positive solution.
